GOALS of meeting

1

• GOALS of meeting
• Discuss status of available detector arrays
• Discuss current developments (both here and
  elsewhere DESPEC, )
• Identify technical know-how in different labs
• Identify and define possible collaborations (FP7
  ??)
• Define goals, contributions, timelines,

NAO Réunion 02/07
2

• Programme
• Introduction Goals, ideas, etc for a new array
  - Nigel Orr
• Status of DESPEC neutron detector array work -
  Daniel Cano Ott
• Two-neutron detection with TONNERRE - Miguel
  Marqués
• Simulations using GEANT4 MENATE - Brian Roeder
• Status of the Neutromania project - Franck
  Delaunay
• Digital electronics developments at LPC - David
  Etasse
• Neutron detection at Bruyeres le Chatel - Xavier
  Ledoux
• Discussion of how to go forward, interests and
  possible contributions from different labs, test
  experiments, etc

NAO Réunion 02/07
3
A New Low-Energy Neutron Detector for the
GANIL-SPIRAL-2 Community ?

• Available detector arrays status
• Current developments
• TONNERRE
• Future low-energy/b-xn array

b-xn, (d,n), (p,n), - direct reactions not
addressed today but requirements very similar

NAO Réunion 02/07
4
Neutron Detector Arrays Available within the
French GANIL-Based Community

• DEMON 96 liquid scintillator modules (LPC,
  IRéS, UCL, ULB)
• EDEN 40 liquid scintillator modules (IPNO)
• ToF ? En , granularity ? q, Q ? n-g
  discrimination
• number of hits x e x ds/dW ? Mn
• TONNERRE 32 Plastic scintillator bars (LPC,
  Bucarest)
• ToF ? En, granularity Dt ? q
• ORION large volume Gd-doped liquid scintillator
• see also presentation by Xavier L. later
  today

5
STATUS of Neutron Detector Arrays Available
within the French GANIL-Based Community

• DEMON majority of modules still in reasonable
  condition
• VXI Daq no longer serviceable
• ? future unclear
• EDEN majority of modules still in good
  condition
• CAMAC limited lifetime, coupling with new
  Daqs
• problematic
• ? future unclear
• TONNERRE upgraded 16 modules/32 PMTs
• VXI GANIL-LPC Daq, VME under
  implementation
• ? available but not well adapted to future
  facilities
• ORION moth balled

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Current Developments within the French
GANIL-Based Community

• New generation (solid) scintillators
• ? ANR L. Stuttgé et al. (Strasbourg-Caen)
• see contribution by Franck D.
• New generation electronics-DAQ
• ? digital daq D. Etasse et al. (LPC)
• manpower BDI requested
• see contribution by David E.
• Exploratory studies/simulations prototype expts
  (2007-2008)
• ? EURISOL SPIRAL-2 (LPC) breakup arrays
  b-n, b-n-n
• see contributions by Brian R. Miguel M.

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TONNERRE Array

• Up to 32 plastic scintillators BC400, 160 x 20
  x 4 cm, d1.2 m
• En by TOF 200 keV lt En lt 5 MeV
• DW ? 45 of 4p
• dE (1 MeV) 80 keV
• e (1 MeV) 50

A. Buta et al., NIM A455 (2000) 412
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TONNERRE Detection Efficiency
A. Buta et al., NIM A455 (2000) 412

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TONNERRE _at_ ISOLDE State-of-the-Art
F Perrot et al., PRC74 (2006)

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TONNERRE Limitations

• Neutron time-of-flight spectra b-decay of
  45Cl28 and 46Cl29

4000 2000 1500 1000 500 0
2000 1000 800 600 400 200 0
46Cl29
46Cl28
45Cl28

S. Grévy and the TONNERRE collaboration
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b-Delayed Neutron Detection Ground Rules for
a Future Detector

• n-g discrimination ? reduce backgrounds, enable
  b-2n,3n ... detection
• ? Liquid scintillators (or new solid
  scintillators)
• improve dEn and eliminate tails in TOF spectra
• ? thin, small volume detectors with increased
  dflight
• lowest possible threshold in En
• ? thin, small volume detectors digital
  electronics
• cross-talk rejection ? enable b-2n, 3n
  detection
• ? modular, highly granular array variable
  geometry
• high eg ? identification of n-decay to excited
  states
• ? large volume high efficiency Ge dets
  (segmented ??)
• (conflict with need for high DWn)